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PloS One 2017In animals, a Western style diet-high in saturated fat and added sugar-causes impairments in hippocampal-dependent learning and memory (HDLM) and perception of internal... (Randomized Controlled Trial)
Randomized Controlled Trial
In animals, a Western style diet-high in saturated fat and added sugar-causes impairments in hippocampal-dependent learning and memory (HDLM) and perception of internal bodily state (interoception). In humans, while there is correlational support for a link between Western-style diet, HDLM, and interoception, there is as yet no causal data. Here, healthy individuals were randomly assigned to consume either a breakfast high in saturated fat and added sugar (Experimental condition) or a healthier breakfast (Control condition), over four consecutive days. Tests of HDLM, interoception and biological measures were administered before and after breakfast on the days one and four, and participants completed food diaries before and during the study. At the end of the study, the Experimental condition showed significant reductions in HDLM and reduced interoceptive sensitivity to hunger and fullness, relative to the Control condition. The Experimental condition also showed a markedly different blood glucose and triglyceride responses to their breakfast, relative to Controls, with larger changes in blood glucose across breakfast being associated with greater reductions in HDLM. The Experimental condition compensated for their energy-dense breakfast by reducing carbohydrate intake, while saturated fat intake remained consistently higher than Controls. This is the first experimental study in humans to demonstrate that a Western-style diet impacts HDLM following a relatively short exposure-just as in animals. The link between diet-induced HDLM changes and blood glucose suggests one pathway by which diet impacts HDLM in humans.
Topics: Adolescent; Adult; Diet Records; Diet, Western; Energy Intake; Female; Humans; Interoception; Male; Mental Recall; Neuropsychological Tests; Recognition, Psychology; Verbal Learning; Young Adult
PubMed: 28231304
DOI: 10.1371/journal.pone.0172645 -
PloS One 2019Is our memory for pairs of items dependent on item characteristics? The present study explores this question using a word learning paradigm; specifically, we examined...
Is our memory for pairs of items dependent on item characteristics? The present study explores this question using a word learning paradigm; specifically, we examined whether referent characteristics, such as referent type (face/object) and familiarity (known/unknown), may influence word-referent mapping. Moreover, we examined this effect across two test sessions to determine if the influence of referent characteristics might be more pronounced over time, and across two age groups (young vs. older adults) to determine if there might be age-related differences. Participants were presented with pseudoword-referent mappings in four referent conditions (face/object × known/unknown) and then were tested with a recognition task immediately after learning, and again after a short delay. Our findings indicated that names for faces were not learned better than names for objects, despite previous literature suggesting that faces are processed differently. We also found that known referents (defined as having a pre-existing label for a referent) were learned better than unknown items but this familiarity advantage was only observed for faces and not for objects. While there were several age-related findings, these might be due to the longer delay between the immediate and delayed tests among the older adults relative to young adults. Taken together, our results suggest that certain referent characteristics do interact and influence our learning of and memory for such pairings.
Topics: Adult; Age Factors; Aged; Female; Humans; Male; Middle Aged; Multilingualism; Recognition, Psychology; Semantics; Singapore; Verbal Learning; Vocabulary; Young Adult
PubMed: 31291370
DOI: 10.1371/journal.pone.0219552 -
The developmental neural substrates of Hebb repetition learning and their link with reading ability.Human Brain Mapping Oct 2020Hebb repetition learning is a fundamental learning mechanism for sequential knowledge, such as language. However, still little is known about its development. This fMRI...
Hebb repetition learning is a fundamental learning mechanism for sequential knowledge, such as language. However, still little is known about its development. This fMRI study examined the developmental neural substrates of Hebb repetition learning and its relation with reading abilities in a group of 49 children aged from 6 to 12 years. In the scanner, the children carried out an immediate serial recall task for syllable sequences of which some sequences were repeated several times over the course of the session (Hebb repetition sequences). The rate of Hebb repetition learning was associated with modulation of activity in the medial temporal lobe. Importantly, for the age range studied here, learning-related medial temporal lobe modulation was independent of the age of the children. Furthermore, we observed an association between regular and irregular word reading abilities and the neural substrates of Hebb repetition learning. This study suggests that the functional neural substrates of Hebb repetition learning do not undergo further maturational changes in school age children, possibly because they are sustained by implicit sequential learning mechanisms which are considered to be fully developed by that age. Importantly, the neural substrates of Hebb learning remain significant determinants of children's learning abilities, such as reading.
Topics: Aptitude; Brain Mapping; Child; Child Development; Female; Humans; Magnetic Resonance Imaging; Male; Memory, Short-Term; Reading; Serial Learning; Speech Perception; Temporal Lobe; Verbal Learning
PubMed: 32573904
DOI: 10.1002/hbm.25099 -
Neurobiology of Learning and Memory Mar 2021Exploration of novel environments has reliably been shown to enhance learning in rodents. More recently, these effects have been replicated in humans using virtual...
Exploration of novel environments has reliably been shown to enhance learning in rodents. More recently, these effects have been replicated in humans using virtual reality: Memory is enhanced after exploration of novel compared to familiar virtual environments. However, exploration of a novel versus familiar environment differs in another aspect. Navigating familiar territory can rely more on habits, while navigating new territory requires active decision-making. This difference in choices could contribute to the positive effects of novelty exploration on memory. In this study, we aimed to investigate this possibility. Participants familiarized with a virtual environment (day 1) and were exposed to this environment again (day 2 or 3) and to a novel environment (day 2 or 3). Participants either actively explored the environments or were passively exposed to the exploration behavior of another participant in virtual reality. After exposure to the environment, participants performed a word-learning task and filled out questionnaires regarding virtual presence and the novelty seeking personality trait. Mixed models suggested that memory performance was higher after participants actively explored versus were passively exposed to a novel environment, while these effects were reversed for a familiar environment. Bayesian statistics provided further weak evidence that memory performance was influenced by the interaction between novelty and exposure type. Taken together, our findings suggest that active exploration may contribute to novelty-induced memory benefits, but future studies need to confirm this finding.
Topics: Adult; Decision Making; Exploratory Behavior; Female; Humans; Male; Memory; Memory, Long-Term; Personality; Recognition, Psychology; Verbal Learning; Virtual Reality; Young Adult
PubMed: 33592311
DOI: 10.1016/j.nlm.2021.107403 -
Developmental Cognitive Neuroscience Dec 2022Implicit learning about new words by picking up on associative information in the contexts they appear in is an important aspect of vocabulary growth. The current study...
Implicit learning about new words by picking up on associative information in the contexts they appear in is an important aspect of vocabulary growth. The current study investigated the neural correlates that underlie how school-aged children and adolescents identify the meaning of novel words embedded within sentence contexts. Importantly, we examine how differences in the brain response to novel words and their context differ as a function of 1) explicit learning success, i.e., whether novel word meanings can be correctly estimated in isolation after a learning opportunity, and 2) individual differences in offline language aptitude as well as age across our cohort (N = 82; 8-16 years). Using a regression-based analysis, we identified the unique influence of these individuals difference metrics by using both measures within the same series of models. The most notable finding from our analysis was a frequency-specific dissociation between the way age and language abilities held relationships with task-relevant oscillatory activity during the novel word meaning task: language abilities associated with task-relevant changes in beta band activity during sentence processing, while age associated with task-relevant changes in theta band activity during pseudoword processing. These effects reflect the how the neural correlates of mapping semantic meaning from sentence contexts-an important skill for word learning-is uniquely influenced by the maturity of language abilities as well as age.
Topics: Adolescent; Child; Humans; Semantics; Vocabulary; Language; Verbal Learning; Electroencephalography
PubMed: 36521344
DOI: 10.1016/j.dcn.2022.101185 -
Brain Research Jul 2012We performed a Delayed-Item-Recognition task to investigate the neural substrates of non-verbal visual working memory with event-related fMRI ('Shape task'). 25 young...
We performed a Delayed-Item-Recognition task to investigate the neural substrates of non-verbal visual working memory with event-related fMRI ('Shape task'). 25 young subjects (mean age: 24.0 years; STD=3.8 years) were instructed to study a list of either 1, 2 or 3 unnamable nonsense line drawings for 3s ('stimulus phase' or STIM). Subsequently, the screen went blank for 7s ('retention phase' or RET), and then displayed a probe stimulus for 3s in which subjects indicated with a differential button press whether the probe was contained in the studied shape-array or not ('probe phase' or PROBE). Ordinal Trend Canonical Variates Analysis (Habeck et al., 2005a) was performed to identify spatial covariance patterns that showed a monotonic increase in expression with memory load during all task phases. Reliable load-related patterns were identified in the stimulus and retention phase (p<0.01), while no significant pattern could be discerned during the probe phase. Spatial covariance patterns that were obtained from an earlier version of this task (Habeck et al., 2005b) using 1, 3, or 6 letters ('Letter task') were also prospectively applied to their corresponding task phases in the current non-verbal task version. Interestingly, subject expression of covariance patterns from both verbal and non-verbal retention phases correlated positively in the non-verbal task for all memory loads (p<0.0001). Both patterns also involved similar frontoparietal brain regions that were increasing in activity with memory load, and mediofrontal and temporal regions that were decreasing. Mean subject expression of both patterns across memory load during retention also correlated positively with recognition accuracy (d(L)) in the Shape task (p<0.005). These findings point to similarities in the neural substrates of verbal and non-verbal rehearsal processes. Encoding processes, on the other hand, are critically dependent on the to-be-remembered material, and seem to necessitate material-specific neural substrates.
Topics: Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Memory, Short-Term; Multivariate Analysis; Photic Stimulation; Psychomotor Performance; Recognition, Psychology; Verbal Learning; Visual Perception; Young Adult
PubMed: 22652306
DOI: 10.1016/j.brainres.2012.05.045 -
Developmental Medicine and Child... Feb 2007Duchenne muscular dystrophy (DMD) is a progressive pediatric disorder that affects both muscle and brain. Children with DMD have mean IQ scores that are about one... (Comparative Study)
Comparative Study
Duchenne muscular dystrophy (DMD) is a progressive pediatric disorder that affects both muscle and brain. Children with DMD have mean IQ scores that are about one standard deviation lower than population means, with lower Verbal IQ than Performance IQ scores. For the present study, verbal skills and verbal memory skills were examined in males with DMD with the Clinical Evaluation of Language Fundamentals, 3rd edition, and the California Verbal Learning Test for Children. Performance of 50 males with DMD (age range 6-14 y, mean 9 y 4 mo [SD 2 y 1 mo]) was compared to normative values. Two subsets of the probands were also compared with two comparison groups: unaffected siblings (n=24; DMD group age range 6-12 y, mean 9 y 1 mo [SD 1 y 8 mo]; sibling age range 6-15 y, mean 9 y 11 mo [SD 2 y 4 mo]) and males with cerebral palsy (CP); (n=23; DMD group age range 6-9 y, mean 7 y 8 mo [SD 1 y 2 mo]; CP age range 6-8 y, mean 6 y 8 mo [SD 0 y 8 mo]). Results demonstrated that although males with DMD performed slightly more poorly than normative values, they performed comparably to the controls on most measures. Consistent deficits were observed only on tests requiring immediate repetition for verbal material (Recalling Sentences, and Concepts and Directions). On other language tasks, including tests of understanding and use of grammar, and understanding of semantic relationships, the males with DMD performed well. Moreover, the males with DMD performed well on multiple indices of verbal recall, and there was no evidence of declarative memory deficits. DMD is a single-gene disorder that is selectively associated with decreased verbal span capacity, but not impaired recall.
Topics: Adolescent; Child; Disabled Persons; Humans; Language Tests; Male; Memory; Multivariate Analysis; Muscular Dystrophy, Duchenne; Neuropsychological Tests; Siblings; Verbal Behavior; Verbal Learning
PubMed: 17254000
DOI: 10.1111/j.1469-8749.2007.00123.x -
PloS One 2012Delayed recall of words in a verbal learning test is a sensitive measure for the diagnosis of amnestic mild cognitive impairment (aMCI) and early Alzheimer's disease...
Delayed recall of words in a verbal learning test is a sensitive measure for the diagnosis of amnestic mild cognitive impairment (aMCI) and early Alzheimer's disease (AD). The relative validity of different retention intervals of delayed recall has not been well characterized. Using the Auditory Verbal Learning Test-Huashan version, we compared the differentiating value of short-term delayed recall (AVL-SR, that is, a 3- to 5-minute delay time) and long-term delayed recall (AVL-LR, that is, a 20-minute delay time) in distinguishing patients with aMCI (n = 897) and mild AD (n = 530) from the healthy elderly (n = 1215). In patients with aMCI, the correlation between AVL-SR and AVL-LR was very high (r = 0.94), and the difference between the two indicators was less than 0.5 points. There was no difference between AVL-SR and AVL-LR in the frequency of zero scores. In the receiver operating characteristic curves analysis, although the area under the curve (AUC) of AVL-SR and AVL-LR for diagnosing aMCI was significantly different, the cut-off scores of the two indicators were identical. In the subgroup of ages 80 to 89, the AUC of the two indicators showed no significant difference. Therefore, we concluded that AVL-SR could substitute for AVL-LR in identifying aMCI, especially for the oldest patients.
Topics: Aged; Aged, 80 and over; China; Cognitive Dysfunction; Female; Humans; Male; Memory; Middle Aged; ROC Curve; Time Factors; Verbal Learning
PubMed: 23236445
DOI: 10.1371/journal.pone.0051157 -
Consciousness and Cognition Jan 2015The basic-systems approach (Rubin, 2005, 2006) states that autobiographical memory is supported by other cognitive systems and argues that autobiographical memories are...
The basic-systems approach (Rubin, 2005, 2006) states that autobiographical memory is supported by other cognitive systems and argues that autobiographical memories are constructed from interactions between cognitive systems, such as language, vision and emotion. Although deficiencies in one or more of the basic systems influence the properties of autobiographical memories, little is known about how these cognitive abilities and autobiographical memory are related. To assert whether participants with stronger cognitive abilities also perform better on autobiographical memory tests, participants who completed verbal and visuospatial memory tests also recorded one personal event, which they recalled after a certain interval. Participants who performed well on the verbal memory tests also had better retention for the personal event, providing support for the basic-systems approach to autobiographical memory and preliminary support for the view that people have more memories from adolescence and early adulthood because the memory system works optimally in these lifetime periods.
Topics: Adolescent; Adult; Age Factors; Aged; Aged, 80 and over; Cognition; Cues; Emotions; Female; Humans; Male; Memory, Episodic; Middle Aged; Spatial Memory; Verbal Learning; Young Adult
PubMed: 25460237
DOI: 10.1016/j.concog.2014.10.001 -
Memory & Cognition Feb 2011Can learners accurately judge the rate of their learning? Rates of learning may be informative when study time is allocated across materials, and students' judgments of...
Can learners accurately judge the rate of their learning? Rates of learning may be informative when study time is allocated across materials, and students' judgments of their learning rate have been proposed as a possible metacognitive tool. Participants estimated how much they improved between presentations in multitrial learning situations in which n-gram paragraphs (in Experiments 1 and 2) or word pairs (Experiments 3 and 4) were learned . In the first experiment, participants rated improvement on a percentage scale, whereas on the second and third, judgments were given on a 0-6 scale. Experiment 4 used both a percentage scale and an absolute number scale. The main result was that judgments of improvement were poorly correlated with actual improvement and, in one case, were negatively correlated. Although judgments of improvement were correlated with changes in judgments of learning, they were not reliable indicators of actual improvement. Implications are discussed for theoretical work on metacognition.
Topics: Humans; Judgment; Mental Recall; Paired-Associate Learning; Retention, Psychology; Verbal Learning
PubMed: 21264622
DOI: 10.3758/s13421-010-0019-2